how to change wire.h file?

Projects Programming
1

I have a newer version of arduino IDE so Wire.h is included in the standard library. I can see the file inside this directory structure

C:\Program Files (x86)\Arduino\libraries\Wire

I want to make the following change

IMPORTANT:
change arduino wire library about I2C buffer.
1.arduino-1.0.5\libraries\Wire\utility\twi.h
#define TWI_BUFFER_LENGTH 255
2.arduino-1.0.5\libraries\Wire\Wire.h
#define BUFFER_LENGTH 255
*******************************************/

When i edit the Wire.h file and try to save it in notepad++, it gives the error

"Please check if this file is opened in another program"

and doesn't let me edit this file. I was wondering how can i edit this file if possible?

2

i'm guessing this is an Operating System issue - is your Arduino IDE still open while you're trying to edit the H file ?
and specifically one with an #include <wire.h> ?

3

no everything is closed. Is there any other way to go about editing Wire.h?

4

ok it is fixed now. I opened notepad++ in administrator mode and it let me edit the file. : )

5

heh-heh, so it was an OS issue :slight_smile:

6

I am wanting to disable the internal pull-up resistors on my Uno board as I'm trying to daisy chain multiple I2C sensors. Per varesano.net -, I am to comment out the following two commands in the twi.c file found in the utilities folder of the wire library:

// activate internal pullups for twi.
digitalWrite(SDA, 1);
digitalWrite(SCL, 1);

When I edited the file to comment out these two lines, the Notepad editor will not let me SAVE the file.

Would someone please provide guidance as to how I could accomplish this modification.

Thank you,

7

Get administrative rights on your PC?
Do a Save As, put the file someplace else copy it back to the directory?

8

I had a similar problem recently after some Win7Pro update. Had to go at the folder level and change the properties so I could make changes to files.

9

Thank you, it appears your suggestion worked by saving the edited file to another folder, then pasting it to the Wire's Utility folder. I'll confirm here with another post if the system works as desired with the four I2C sensors.